Hi Egol,
Yes I have done it
- so if part of your question was a technical 'is this possible?' then it is. You can check which pages your ads are showing on by going into display network -> placements and then clicking the 'see details' button. This will give you a list of specific page placements which ran your ad.
As to if it is worth it or not, that depends on a lot of factors including what objective you have in mind, your budget etc.
I will say that running keyword + placements together often results in a very narrow set of pages that your ad becomes eligible for. This can be ok depending on the objective of the campaign but I often find that it is better to either run broader keyword only campaigns which I then add negative placements to (if I see placement sites I don't like much) or else run a very specific managed placement campaign with certain exclusions based on the categories of the site(s) if needed.
Bid levels vary a lot depending on the site and how many other advertisers want to appear there. Well known sites like the NYTimes are usually going to be more expensive than a niche site but it all depends on your targeting, what you are willing to bid and what any other advertisers are willing to bid. if a specific site is turning out to be too expensive to bid on then you could try making it a remarketing only campaign which restricts your ads to people that have already visited your site and you might then feel more comfortable bidding a higher amount for them to see your ad. If you have historical conversion data on the campaign it might also be worth trying a CPA bidding model to see if that works better for you.
n my experience display campaigns are great for remarketing and branding/awareness type campaigns but can really suck up budget if not controlled properly and kept on a tight leash.